Gas chromatography-olfactometry

Abstract

ReviewGas chromatography-olfactometry GC-olfactometry (GC-O) refers to the use of human assessors as a sensitive and selective detector for odour-active compounds. The aim of this technique is to determine the odour activity of volatile compounds in a sample extract, and assign a relative importance to each compound. Methods can be classified into three types: detection frequency, dilution to threshold and direct intensity. Dilution to threshold methods measure the potency of odour-active compounds by using a series of extract dilutions, whereas detection frequency and direct-intensity methods measure odouractive compound intensity, or relative importance, in a single concentrated extract. Factors that should be considered to improve the value of GC-O analysis are the extraction method, GC instrument conditions, including the design and operation of the odour port, methods of recording GC-O data and controlling the potential for human assessor bias using experimental design and a trained panel. Considerable emphasis is placed on the requirement for multidimensional GC analysis, and on best practice when using human assessors.

Characterization of Volatiles and Aroma-Active Compounds in Honeybush (Cyclopia subternata) by GC-MS and GC-O Analysis

“…This aspect will be highlighted in a future study comparing the aroma profiles of a number of Cyclopia species. Existing GC-O methodologies have been reviewed in detail by Delahunty et al (13) In the present study, DF and aroma extract dilution analysis (AEDA) were chosen as aroma evaluation techniques for the identification of the aroma-active compounds in fermented honeybush. A total of 37 components were found to be odor-active (FD ≥ 2) ( Table 1, …”

Identification Odor Compounds Emitted During the Heating of Molding Sands

“…Olfactometric qualitative analysis are released gases were conducted by gas chromatography [15] using a portable equipment zNose® 4300 dedicated to the detection of flavor compounds from the group of alkanes (ie. "e-nose") [8,16,17].…”

Headspace solid‐phase microextraction and gas chromatography–olfactometry analysis of raw spirits of different organoleptic quality

“…Samples were delivered by local agricultural distilleries (Pomeranian region). The raw spirits selected for this study (39 samples) differed in organoleptic properties; 13 of them reached the highest rating from sensory analysis performed in accordance with Polish Standard PN-A-79 528-2:2002 (samples 27-39); 13 spirits received diverging ratings during the sensory analysis-some of the evaluating panelists found them to satisfy the standard, some rated otherwise (samples [14][15][16][17][18][19][20][21][22][23][24][25][26]; the remaining 13 samples did not fulfil the organoleptic requirements (samples 1-13). Preliminary sensory analyses of samples were carried out in the laboratory of Sobieski Distillery.…”

“…Every man has distinct olfactometric abilities. A common fact is the occurrence of so-called specific anosmia, which manifests itself in loss or reduced ability to detect some odours or odour categories [21] . A specific increased susceptibility to some odours is also possible.…”

“…Although the chromatographic peaks in many poor-quality samples were higher than in the remaining ones, only part of these samples could be singled out with the use of an olfactometric detector. Of course, one should not forget the possibility of the effects of mutual masking, elimination or enhancement by aroma compounds appearing side by side, and even of odourless compounds eluting along with aroma compounds [21] . Besides, it should be remembered that the detection limits and linearity ranges of the two detectors were completely different (in the case of a human nose this meant rather thresholds of sensory perceptibility and the course of psychometric functions of individual compounds), therefore no high correlation between surface areas of chromatographic and olfactometric peaks should be expected.…”